safe distances are? and what type of ammo,like leadnose only or if you could use fmj if the the steel is angled down?

CAS shoots as close as 7 yards at steel, Ive seen folks shoot a lot closer with no harm, but Id say its pushing it closer than that. The downwards directed angle is the key with any ammo used. With a very subtle angle, lead round nose bullets and wad-cutters pancake and fall nearly vertically, straight down. Jacket-less, lead ammo is generally considered safe.

FMJ, even semi-jacketed bullets can potentially separate and come back towards the shooter, avoid them when shooting steel.